Immunogenicity and Reactogenicity of an Inactivated Quadrivalent Influenza Vaccine Administered Intramuscularly to Children 6 to 35 Months of Age in 2012-2013: A Randomized, Double-Blind, Controlled, Multicenter, Multicountry, Clinical Trial.

Bottom Line:
The immunogenic superiority of the additional B/Victoria strain in the QIV compared to that in the TIV was confirmed: the LL of the 2-sided 95% CI of the geometric mean titer ratio (QIV/TIV) (6.28 [95% CI, 5.32-7.41]) was greater than 1.5, and the LL of the 2-sided 95% CI for the difference in the seroconversion rate (QIV - TIV) (64.19% [95% CI, 57.65%-69.95%]) was greater than 10%.Injection-site pain and irritability/fussiness were the most commonly reported solicited injection-site and general adverse events, respectively, from days 0 to 6 and were similar in frequency between the groups.In children aged 6 to 35 months, a QIV has superior immunogenicity for the added B strain and acceptable immunogenicity for shared strains, with no notable difference in reactogenicity and safety when compared to a TIV.

Background: Influenza attack rates are high in 6- to 35-month-old children; vaccines containing both lineages of influenza B (Yamagata and Victoria), in addition to the H3N2 and H1N1 antigens, may improve protection rates.

Methods: In a randomized double-blind controlled trial, the immunogenicity and reactogenicity of an inactivated quadrivalent influenza vaccine (QIV) and a trivalent control vaccine (TIV) were assessed.

Results: Six hundred one children (QIV, n = 299; TIV, n = 302) were enrolled at 8 sites in 3 countries. The primary immunogenicity objective was met: the lower limit (LL) of the 2-sided 95% confidence interval (CI) for the seroconversion rate in QIV recipients ranged from 66.6% to 81.3%, which was ≥40% against all 4 strains. The immunogenic superiority of the additional B/Victoria strain in the QIV compared to that in the TIV was confirmed: the LL of the 2-sided 95% CI of the geometric mean titer ratio (QIV/TIV) (6.28 [95% CI, 5.32-7.41]) was greater than 1.5, and the LL of the 2-sided 95% CI for the difference in the seroconversion rate (QIV - TIV) (64.19% [95% CI, 57.65%-69.95%]) was greater than 10%. Injection-site pain and irritability/fussiness were the most commonly reported solicited injection-site and general adverse events, respectively, from days 0 to 6 and were similar in frequency between the groups.

Conclusions: In children aged 6 to 35 months, a QIV has superior immunogenicity for the added B strain and acceptable immunogenicity for shared strains, with no notable difference in reactogenicity and safety when compared to a TIV.

PIU098F3: Immunogenic superiority of QIV versus TIV-YB for the B Victoria strain in the ATP cohort for immunogenicity. Adjusted GMT indicates GMT adjusted for baseline titer; SCRs, an antibody titer of ≥40 1/DIL after vaccination for initially seronegative subjects and an antibody titer after vaccination of ≥4-fold the prevaccination antibody titer for initially seropositive subjects. Criteria for superiority were that the LL of the 2-sided 95% CI of the GMT ratio (Q-QIV /D-TIV-YB) was >1.5 and the LL of the 2-sided 95% CI on the SCR difference (Q-QIV – D-TIV-YB) was >10%. Error bars indicate 95% CIs.

Mentions:
The immunogenic superiority of the B/Victoria strain present in the QIV (in terms of GMT and SCR) over that in the TIV was concluded, because the LL of the 2-sided 95% CI of the adjusted GMT ratio (QIV/TIV) (6.28 [95% CI, 5.32–7.41]) was greater than 1.5, and the LL of the 2-sided 95% CI for the difference in SCRs (QIV – TIV, 64.19% [95% CI, 57.65%–69.95%]) was greater than 10% (Figure 3). The adjusted GMT ratio (adjusted for HI antibody titers at baseline) was 6.28 (95% CI, 5.32–7.41).Figure 3.

Immunogenicity and Reactogenicity of an Inactivated Quadrivalent Influenza Vaccine Administered Intramuscularly to Children 6 to 35 Months of Age in 2012-2013: A Randomized, Double-Blind, Controlled, Multicenter, Multicountry, Clinical Trial.

PIU098F3: Immunogenic superiority of QIV versus TIV-YB for the B Victoria strain in the ATP cohort for immunogenicity. Adjusted GMT indicates GMT adjusted for baseline titer; SCRs, an antibody titer of ≥40 1/DIL after vaccination for initially seronegative subjects and an antibody titer after vaccination of ≥4-fold the prevaccination antibody titer for initially seropositive subjects. Criteria for superiority were that the LL of the 2-sided 95% CI of the GMT ratio (Q-QIV /D-TIV-YB) was >1.5 and the LL of the 2-sided 95% CI on the SCR difference (Q-QIV – D-TIV-YB) was >10%. Error bars indicate 95% CIs.

Mentions:
The immunogenic superiority of the B/Victoria strain present in the QIV (in terms of GMT and SCR) over that in the TIV was concluded, because the LL of the 2-sided 95% CI of the adjusted GMT ratio (QIV/TIV) (6.28 [95% CI, 5.32–7.41]) was greater than 1.5, and the LL of the 2-sided 95% CI for the difference in SCRs (QIV – TIV, 64.19% [95% CI, 57.65%–69.95%]) was greater than 10% (Figure 3). The adjusted GMT ratio (adjusted for HI antibody titers at baseline) was 6.28 (95% CI, 5.32–7.41).Figure 3.

Bottom Line:
The immunogenic superiority of the additional B/Victoria strain in the QIV compared to that in the TIV was confirmed: the LL of the 2-sided 95% CI of the geometric mean titer ratio (QIV/TIV) (6.28 [95% CI, 5.32-7.41]) was greater than 1.5, and the LL of the 2-sided 95% CI for the difference in the seroconversion rate (QIV - TIV) (64.19% [95% CI, 57.65%-69.95%]) was greater than 10%.Injection-site pain and irritability/fussiness were the most commonly reported solicited injection-site and general adverse events, respectively, from days 0 to 6 and were similar in frequency between the groups.In children aged 6 to 35 months, a QIV has superior immunogenicity for the added B strain and acceptable immunogenicity for shared strains, with no notable difference in reactogenicity and safety when compared to a TIV.

Background: Influenza attack rates are high in 6- to 35-month-old children; vaccines containing both lineages of influenza B (Yamagata and Victoria), in addition to the H3N2 and H1N1 antigens, may improve protection rates.

Methods: In a randomized double-blind controlled trial, the immunogenicity and reactogenicity of an inactivated quadrivalent influenza vaccine (QIV) and a trivalent control vaccine (TIV) were assessed.

Results: Six hundred one children (QIV, n = 299; TIV, n = 302) were enrolled at 8 sites in 3 countries. The primary immunogenicity objective was met: the lower limit (LL) of the 2-sided 95% confidence interval (CI) for the seroconversion rate in QIV recipients ranged from 66.6% to 81.3%, which was ≥40% against all 4 strains. The immunogenic superiority of the additional B/Victoria strain in the QIV compared to that in the TIV was confirmed: the LL of the 2-sided 95% CI of the geometric mean titer ratio (QIV/TIV) (6.28 [95% CI, 5.32-7.41]) was greater than 1.5, and the LL of the 2-sided 95% CI for the difference in the seroconversion rate (QIV - TIV) (64.19% [95% CI, 57.65%-69.95%]) was greater than 10%. Injection-site pain and irritability/fussiness were the most commonly reported solicited injection-site and general adverse events, respectively, from days 0 to 6 and were similar in frequency between the groups.

Conclusions: In children aged 6 to 35 months, a QIV has superior immunogenicity for the added B strain and acceptable immunogenicity for shared strains, with no notable difference in reactogenicity and safety when compared to a TIV.